As more wired and wireless networks are installed across the country, an increased demand is placed on authenticating users and networked resources prior to commencing an electronic transaction. That is, users normally require a level of trust to be established prior to performance of an electronic transaction. One technique for establishing a level of trust is the use of digital certificates.
A “digital certificate” is an electronic data structure utilized in a public key infrastructure (PKI) system for security purposes. One common use of a digital certificate is to verify the sender of a message. Another use of a digital certificate is to transfer keys in an encrypted format to avoid them being sent in clear.
Digital certificates are normally obtained by an applicant upon supplying his or her unique public key (PUKA) and identity, among other information, to a certificate authority (CA). Examples of a CA include, but are not limited or restricted to, any trusted establishment such as a bank, an escrow service, a governmental entity, a trusted third party (e.g., Verisign), or the like.
More specifically, in response to receiving PUKA from an applicant, the CA creates a digital certificate by digitally signing the PUKA and other selected information using a private key of the CA (hereinafter referred to as “PRKCA”). Since CA makes its own public key readily available to the public, a recipient may recover PUKA from the CA-signed digital certificate.
For instance, the recipient of an encrypted message accompanied with the CA-signed digital certificate uses PUKCA to decode this digital certificate and to verify that the CA issued this digital certificate. The sender's public key (PUKA) and other information may be recovered, which allows the recipient to send an encrypted reply to the sender using PUKA. The most widely used standard for digital certificates is the CCITT Recommendation X.509: The Directory—Authentication Framework (1988).
Over the last few years, there has been a growing movement toward Internet protocol (IP) based telephony. IP telephony involves the transmission of telephone calls in digital form over an IP based data network Voice-Over-IP (VoIP) is an IP telephony term for a set of facilities used to manage the delivery of voice information over the Internet. Voice is delivered by packetizing voice streams.
VoIP converts the voice signals from the telephone into a digital signal that can be transmitted across the data network. At the receiving end, the digital signal is converted back to voice. The basic telephone functions between traditional voice and VoIP are identical. User picks up the receiver handset, hears a dial tone, and dials the phone number as they have been done in the past. Benefits behind IP telephony include, but are not limited to, cost savings realized by the users and improved productivity with advanced features such as mobility. However, security is among the top concern of many users with VoIP. To improve security of IP telephony, public key based techniques using digital certificates have been widely implemented in IP telephony solutions including IP phones.
The growing usage of IP phones on networks that use public key based techniques for security has highlighted an emerging problem with digital certificate installation, especially the growing difficulties experienced by network administrators.
For instance, IP phones using public key based techniques usually require secure installation of a CA digital certificate into the trusted certificate list (TCL) of the IP phone before configuration files can be securely downloaded. The configuration files are used to configure the initial settings of the IP phone, normally at the OSI Application layer. One problem posed is how to allow new IP phones, without any on-site configuration, to verify a digitally signed configuration file. Currently, this requires a network administrator to perform such verification on a phone-by-phone basis, which is a time-consuming task.
It is desirable to develop a digital certificate installation technique that can be used by IP phones or other network devices to become quickly functional upon being connected to the network with minimal user and administrative intervention, and a high degree of security.